1. Technical Field
The present invention relates to a fixation device for an electronic display, particularly to a device for fixing an electronic display on a printed circuit board of electronic apparatuses with high stability by a simple attaching operation.
2. Prior Art
An electronic display such as a liquid-crystal or fluorescent display tube for digitally or graphically showing a volume of sound, frequency, revolution speed, time measurement result or the like is attached to a home electric appliances such as a television set, a radio, a video tape recorder, a microwave oven, a stereo, and a measuring instrument.
Various methods for mounting such electronic displays into electric appliances have been proposed. For example, FIG. 12 is a schematic sectional view showing an example of a conventional mounting method, in which a double-coated tape or adhesive 41 is adhered onto a circuit board 40, then a buffer material 42 such as, for example, a sponge made of chloroprene is stuck onto the tape or adhesive 41, further, a double coated tape or adhesive 43 is adhered to the buffer material 42, and the back of an electronic display 44 is fixed adhesively to the tape or adhesive 43, while terminals 45 extending from the electronic display 44 are inserted into through holes formed in the circuit board 40 to support the electronic display 44.
In such fixing method, however, the application of the adhesive and the removal of a release paper from the double-coated tape are troublesome, and particularly when an adhesive is used, its drying takes time. Further, it is difficult to dispose the electronic display 44 in a predetermined position. The display 44 is apt to be dislocated, and its terminals 45 are easily bent under a one-sided load imposed thereon, and so are difficult to be inserted into the through holes formed in the circuit board 40. Also for maintenance, various drawbacks are involved in such fixing method, for example, the electronic display 44 once mounted is difficult to remove, and the height is not stabilized.
Various fixation devices for installing electronic display parts into electronic apparatuses have been proposed. For example, in the U.S. Pat. No. 4,684,093, some fixation devices are described.
Those fixation devices described in U.S. Pat. No. 4,684,093 are shown in FIGS. 13 through 15 and FIG. 16 attached herewith.
In the prior art, fixation devices 50 and 150 comprise at least two holding members 52 and 152 formed at corners of a plate-like rest 51 and 151 so as to pivot via hinges 54 and 154 for retaining an electronic display 55. Engaging members 59 and 159 are formed at the other corner of the rest 51 and 151 as opposed to the hinges 54 and 154 for engaging each free end of the holding members 52 and 152 at the position where the above mentioned electronic display 55 is retained by the holding members 52 and 152. Fixing members 56a extend from the back surface of the plate-like rest 51 and 151 for fixing the rest 51 and 151 on a circuit board 57.
However, the above mentioned fixation devices 50 and 150 have the following problems. (1) The holding members 52 and 152 have to greatly pivot at large angles, which is from 90 to 180 degrees, via hinges 54 and 154 when attaching and demounting of the electronic display 55. (2) An extra space around the fixation device 50 and 150 has to be reserved when the holding members 52 and 152 are pivotably turned at large angles without difficulties. (3) Durability of the hinges 54 and 154 is rather poor because of the hard activities imposed upon the hinges 54 and 154 at the time of pivoting. (4) The hinges 54 and 154 tend to become damaged when the holding members 52 and 152 are engaged for a long time for transportation. (5) In order to avoid the preceding problems packaging efficiency is lowered because the holding members 52 and 152 should be completely opened, as shown in FIGS. 13 and 16.